1. Field of the Invention
The present invention relates generally to a charge pump circuit which can be used as a positive and negative charge pump, more particularly to a charge pump circuit in which the area of layout is reduced by making the positive and negative charge pump in a single circuit, and the efficiency of the pump is enhanced and in which the pumping speed becomes high by making the driving voltage high.
2. Description of Prior Art
Generally, memory devices need charge pumps which convert cell data to current signals, and the charge pumps can be divided into positive and negative charge pumps by the characteristics of the output charge. In a conventional charge pump circuit, the positive and negative charge pumps are separately constructed to obtain the desired voltage levels.
Accordingly, the conventional charge pump circuit has some problems in that a degree of integrated is low since the required capacitance of each pumping circuit is high, the quantity of transferred charges is small since the fixed power source is used as driving voltage of a pumping capacitor, and the quantity of charge losses is high since there are a number of diodes which transferring the charges.